Correct Answer: B

Rationale: To convert milligrams to grams, you need to divide by 1,000 since there are 1,000 milligrams in 1 gram. Therefore, 5,000 milligrams is equal to 5 grams (5,000 · 1,000 = 5). Choice A, '50 grams,' is incorrect as it results from multiplying instead of dividing. Choice C, '500 grams,' is incorrect as it incorrectly multiplies the value. Choice D, '0.05 grams,' is incorrect as it is the result of dividing by 10 instead of 1,000.

Correct Answer: B

Rationale: The correct answer is B: 3 feet. This is because 1 yard is equivalent to 3 feet. The conversion factor between yards and feet is 1 yard = 3 feet. Choice A (4 feet) is incorrect as it represents the conversion of 1 yard to 4 feet, which is inaccurate. Choice C (2 feet) is incorrect as it underestimates the number of feet in 1 yard. Choice D (5 feet) is incorrect as it overestimates the number of feet in 1 yard.

Correct Answer: A

Rationale: To find the product of 0.5 and 20, you multiply them together. 0.5 x 20 = 10. This calculation involves multiplying a decimal (0.5) by a whole number (20). Choice A, '10', is the correct answer. Choice B, '15', is incorrect as it does not accurately represent the result of multiplying 0.5 by 20. Choices C and D, '20' and '25', are also incorrect as they do not reflect the correct calculation. This question assesses your ability to perform basic arithmetic operations involving decimals and whole numbers.

Correct Answer: A

Rationale: The correct answer is A: 9. To find the result of multiplying 0.15 by 60, you simply multiply the two numbers together. 0.15 * 60 = 9. This calculation involves basic multiplication. Choices B, C, and D are incorrect as they do not reflect the correct product of 0.15 and 60. Understanding how to multiply decimals and whole numbers is essential in various real-life scenarios such as calculating percentages or adjusting measurements.

Correct Answer: A

Rationale: To convert a decimal to a fraction, you can write the decimal as a fraction with the decimal part as the numerator and a power of 10 as the denominator. In this case, 0.75 can be written as 75/100. Simplifying this fraction by dividing both the numerator and denominator by 25 gives you 3/4. Therefore, the correct answer is A. Choice B (7/10), Choice C (15/20), and Choice D (1/2) are incorrect because they do not represent the correct conversion of 0.75 into a fraction.